Complex Vector Disturbance Observer-Based Deadbeat Predictive Current Controller for PMSM Current Harmonics Suppression

Under complex operating conditions, deadbeat predictive current control (DPCC) is susceptible to multisource disturbances, including periodic and aperiodic components, which degrades the current control accuracy. To address this issue, a DPCC strategy based on a complex vector disturbance observer (CVDO) is proposed for the current loop of permanent magnet synchronous motor (PMSM) drives. First, the structure of the CVDO is developed from the PMSM mathematical model, and its sensitivity function is derived. On this basis, the CVDO is designed in the frequency-domain to achieve precise estimation of multisource disturbances. Distinct from existing observers with embedded resonant structures, the proposed CVDO is designed directly from the perspective of frequency-domain response. This approach achieves ideal frequency-domain characteristics and facilitates stability analysis more intuitive. Benefiting from a unique multi-band synergistic architecture, the proposed method not only achieves the accurate separation and extraction of positive- and negative-sequence harmonics as well as aperiodic disturbances, but also effectively overcomes the disturbance amplification problem inherent in existing methods. Significantly, this architecture allows for the independent adjustment of disturbance estimation across different frequency bands, thereby enabling the independent optimization of observation performance for each band. Thus, this enhances the degrees of freedom in parameter tuning and improves design flexibility. Furthermore, the estimation performance and stability of the observer are analyzed theoretically. Finally, the effectiveness and advantages of the proposed method are validated on a PMSM platform.